(Alkynyloxy)alkyl and (alkenyloxy)alkyl carbamates

ABSTRACT

The invention is novel (alkynyloxy)alkyl and (alkenyloxy)alkyl carbamates and their use as herbicides.

United States Patent Cross et al.

[ Oct. 21, 1975 (ALKYNYLOXY)ALKYL AND (ALKENYLOXY)ALKYL CARBAMATES [75] Inventors: Barrington Cross, Rocky Hill;

Charles Paul Grasso, Cranbury, both of NJ.

[73] Assignee: American Cyanamid Company,

Stamford, Conn.

221 Filed: May 24,1973

21 Appl. No.: 363,783

52 U.S.Cl ..260/47lC;71/l00;7l/111;

260/455 A [51] Int. Cl. C07C 125/06 Primary Examiner-James A. Patten Assistant ExaminerL. A. Thaxton Attorney, Agent, or Firm-H. G. Jackson [57] ABSTRACT The invention is novel (alkynyloxy)alkyl and (alkenyl0xy)alkyl carbamates and their use as herbicides.

7 Claims, No Drawings (ALKYNYLOXY )ALKYL AND (ALKENYLOXY )ALKYL CARBAMATES BACKGROUND OF THE INVENTION 1. Field of the Invention The invention pertains to novel organic chemicals useful as herbicides.

2. Description of the Prior Art m-Ureidophenyl carbamates are described as herbicides in US. Pat. No. 3,434,822 (1969). Similarly, alkoxyalkylcarbamoyloxy phenylureas are described as herbicides in Belgium Pat. No. 742,291 (I970). The compounds described in these patents are shown to be quite effective as preemergence and postemergence herbicides against certain species of undesirable plants when applied at rates between 1.5 pounds and 6 pounds per acre. However, it can also be seen that the activity of the described compounds are generally nonselective and are not recommended for use in the presence of economically important crops, such as com, cotton or soybeans.

It would, therefore, be advantageous if more effective compounds could be found which would provide better control of undesirable plants at even lower rates of application. Surprisingly; we have found that the compounds of our invention are highly effective herbicidal agents when applied at rates as low as 0.06 pound per acre. We have also discovered that the compounds can be used for selective control of undesirable plants in the presence of several agronomic crops, such as corn, cotton or soybeans.

SUMMARY OF THE INVENTION This invention is compounds of the formula:

Ema-c442 1 wherein R is alkyl C,C., alkenyl C,-C., alkynyl C,--C., cycloalkyl C,--C-,, phenyl, benzyl,

X, Y, and Z each represent sulfur and oxygen; A is hydrogen, alkyl C C. or halogen (preferably chlorine, bromine and iodine); R, is

R, and R; are hydrogen or alkyl C,-C (preferably methyl); and R and R, are hydrogen, halogen (preferably chlorine, bromine and iodine) or alkyl C --C (preferably methyl); with the proviso that A and are metaand parato the group, respectively, or paraand meta-, respectively and the compounds use as herbicides.

The invention also relates to novel herbicidal compositions, which contain as the active ingredient a compound having the above formula. The invention further relates to methods for the preemergence and postemergence control of undesirable plant species by applying to the foliage of the undesirable plants, or soil containing seeds of the undesirable plants, a herbicidally effective amount of a compound having the above formula.

DETAILED DESCRIPTION OF THE INVENTION This description describes the invention in more detail and includes the preferred embodiments but is not to be construed as limitative.

In accordance with the invention, bis-carbamates having the above structure can be prepared by reaction of an (alkynyloxy)methyl isocyanate, (alkynyloxy)- methyl isothiocyanate, (alkenyloxy)methyl isocyanate or (alkenyloxy)methyl isothiocyanate with a metaor para-hydroxycarbanilate in the presence of a tertiary base.

The reaction can be illustrated as follows:

II III wherein, R, R,, X, Y, Z and A are as defined above.

In order to obtain bis-carbamates (I), the reaction conditions should be carefully controlled. Best yields are obtained in p-dioxane or tetrahydrofuran as solvents, although various aprotic solvents also give the product. ln practice, the hydroxycarbanilate (ll) is either suspended or dissolved in the organic solvent, although it is found that complete solution is most desirable since higher product yields are obtained under these conditions. Other aprotic solvents which can be used in place of dioxane or tetrahydrofuran are ethers, such as diethyl ether, methyl ethyl ether, and the like, dimethylformamide, acetone, methyl ethyl ketone, methyl isobutyl ketone, and ethyl acetate. The presence of a tertiary base or catalyst is also essential to the preparation of the carbamates of this invention. Gener ally, about one molar equivalent, and preferably an excess of base, is employed. In addition to the tertiary amines, bases (such as pyridine, triisopropylamine and quinoline and dibutyltin diacetate) may also be utilized to catalyze the reaction.

The isocyanates or isothiocyanates (III) are generated by the reaction of silver or sodium cyanate or ammonium or sodium thiocyanate on the appropriate chloromethyl ether. This reaction is generally carried out in ethereal solution (e.g. diethyl ether or tetrahydrofuran), but not isolated, at a temperature between about C. and C. However, other solvent systems, such as acetonitrile-benzene, may also be employed; and in the case of the isothiocyanate, some warming may be required. 7

The cooled, generated isocyanate or isothiocyanate solution is then added slowly to a stirred solution of the hydroxycarbanilate (ll), in the presence of base and solvent. The mixture is stirred, and the solution then evaporated. The residue is washed with 1% ice cold alkali solution and treated with an organic solvent, such as chloroform, to give a final wash or to crystallize the product.

Examples of isocyanates and isothiocyanates (Ill) generated in accordance with the above procedures are listed in Table l below.

Alternatively, if the reaction is carried out in an aprotic solvent that is water miscible i.e. solvents such as dimethylformamide, acetone or dimethylsulfoxide then the work up may be accomplished by pouring the reaction mixture into ice-water, stirring and filtering off the product, followed by crystallization if necessary.

TABLE l Intermediate hydroxycarbanilates that may be used are set forth below in Table ll.

im-c'e-oca TABLE II cont d.

Eydroxzcarbanilates NH-CO-OC 2 5 NH-CO-O-C H -i mi-co-oc u -g NH-OO- mime-0Q NH-CO-O-CH-CECH I CH NH-CO-OCH '.I.A BLE II cont'd.

lj droxzceirbanilates NH-CO-OCH NH-CO-OCl-l NI'l-CS-OCH NH-CS-SCH NI'l-CO-OCH The compounds of this invention are effective herbicidal agents. They provide selective control of a wide variety of broadleaf weeds and grasses and may be used for either preemergence or postemergence control of undesirable plants, and may also be used alone or in combination with other herbicides. Moreover, they can be utilized for the control of undesirable weeds and grasses in the presence of agronomic crops, such as corn, cotton and soybeans.

The active compounds can be incorporated in liquid or solid formulations which are useful for application to the foliage of undesirable plants, or to soil containing seeds of undesirable plants.

Among the solid formulations which can be prepared are dusts, dust concentrates, wettable powders and granular formulations.

Dusts are usually prepared by dissolving the active ingredient in a lower C,-C alcohol or a ketone (e.g. acetone, methyl ethyl ketone or cyclohexanone) and spraying the thus prepared solution on a finely divided carrier, such as attapulgite, talc, kaolin, silica, diatomaceous earth, or the like. Dusts usually contain about 1 to 15% by weight of the active compound.

Dust concentrates are prepared in the same fashion as dusts, excepting that about 16% to about by weight of the active compound is applied to the carrier.

Wettable powders are made up in the same manner as the dust concentrates; however, about I to 5% by weight of a surfactant, and about 1 to 5% by weight of a dispersant, is added to the formulation. The wettable powders are generally dispersed in water or other suitable liquid and applied to the soil or foliage as a dilute spray.

Surfactants which may be used in the preparation of the wettable powders are naphthalene sulfonic acid condensate, polyoxyethylate vegetable oil, Sorbitan monooleate, monoand diglycerides of fatty acids,

'alkyl phenoxy polyoxyethylene ethanol and sodium alkyl naphthalene sulfonate. The monocalcium salt of a polymerized alkyl aryl sulfonic acid and sodium lignin sulfonate are representative of dispersants which can be used in the wettable powder formulations. Other adjuvants can be added to where desired.

Granular formulations can be prepared by applying an alcoholic or ketonic solution of the active material to a granular sorptive carrier such as attapulgite, kaolin, activated carbon or corn cob grits. Non-sorptive carriers, such as granular limestone, walnut shell, coconut shell or sand may be used in the preparation of granular formulations by (l) wetting the granules with a binder solution (e.g. sodium lignosulfonate) or an alcoholic or ketonic solution of the active ingredient, and (2) coating the wetted particles with a dust or dust concentrate containing the active compound or with an inert dusting agent, such as talc or clay.

Emulsifiable concentrates can be prepared by dissolving about 25 to 75% by weight of the active compound in a lower alcohol or ketone, as mentioned above, and admixing therewith from about I to l0% by weight of an emulsifier; for example, an anionic-nonionic emulsifier. For use in the field, the concentrate is usually dispersed in water or other suitable diluent and applied as a liquid spray.

Effective control of a wide variety of broadleaf weeds and grasses is usually obtained by application of a sufficient amount of the formulated composition to provide about 0.25 pound per acre to 8 pounds per acre, and preferably 0.5 pound to 4 pounds per acre of active 3,914,285 7 8 compound. Selective control of said weeds, and successively with 1% aqueous sodium hydroxide (2 X grasses, on the other hand, generally requires only 100 ml.), water(] X 100 ml.), dilute hydrochloric acid about 0.25 pound per acre to about 2 pounds per acre (1 X 100 ml.) and water (1 X 100 ml.). The organic of the active compound. layer is dried over anhydrous CaCl filtered and evapo- This invention is further illustrated by the following 5 rated to give an oil, which solidified on treating with nexamples. hexane. Crystallization from benzene/n-hexane gives 2.47 grams (31%) of product. EXAMPLE 1 Analysis Calculated for c,,H,.N o.. c, 55.71; H, Preparation of Carbanilic acid, m-hydroxy, methyl 5.75; N, 10.00. Found: C, 55,46; H, 5.90; N, 9.96.

ester, ester with [(allyloxy)methyllcarbamic acid l Allyl chloromethyl ether (3.16 grams, 0.03 mole) is EXAMPLE 2 added dropwise with cooling at 5C. and stirring to a Preparation of Carbanilic acid, m-hydroxy-, methyl dry ethereal (33 ml.) suspension of silver cyanate (4.7 ester, ester with grams, 0.032 mole). After stirring at room temperature 1,1-dimethyl-2-propynyloxy)methyllcarbamic acid HC-C OCH,-N=C=O NHCO-OCH,

NH-CO-OCH H 3 HC CC0CH,NHC0O for 1% hours, the completed reaction is filtered and (l,1-Dimethyl-2-propynyloxy)methyl isocyanate added dropwise with stirring to 3-hydroxycarbanilic (0.03 mole) in ether (37.3 ml.) (generated from the acid, methyl ester (5.01 grams, 0.03 mole) in tetrahychloromethyl ether and silver cyanate) is added dropdrofuran ml.) and triethylamine (3.34 grams, 0.03 wise with stirring to a dry tetrahydrofuran solution mole). After the initial exothermic reaction (to 27C.), ml.) of m-hydroxycarbanilic acid, methyl ester (5.01 the mixture is stirred at room temperature for 2% grams, 0.03 mole) containing triethylamine (4 grams, hours. The mixture is evaporated, and the residual oil is 0.039 mole). After the initial exothermic reaction to dissolved in chloroform ml.) which was washed 27C., the mixture is allowed to stir at room tempera- EXAMPLE 3 Preparation of Carbanilic acid, 3-chloro-4-hydroxy-, methyl ester, ester with l, l -dimethyl-2propynyloxy )methyllcarbamic acid.

An ether solution (37.3 ml.) of(l,l-dimethyl-Z- propynyloxy)methyl isocyanate (0.03 mole) is added dropwise with stirring to tetrahydrofuran (25 ml.) conl0 taining 3-chloro-4-hydroxycarbanilic acid, methyl ester (6.92 grams, 0.03 mole) and triethylamine (4 grams, 0.039 mole). After 3 hours at room temperature, the mixture is evaporated to a residual oil which is dissolved in chloroform and successively washed with 1% aqueous sodium hydroxide (2 X 100 ml.), water (1 X 100 ml.), 10% aqueous hydrochloric acid (1 X 100 ml.) and water (1 X 100 ml.). After drying over anhydrous CaCl, and filtering, the solution is evaporated to an oil. Crystallization from benzene gives 1.42 grams (14%), melting point 119 to 120C.

Anaylsis Calculated for C -,H, N,O cl: C, 52.87; H, 5.03; N, 8.22. Found: C, 53.15; H, 5.07; N, 8.17.

EXAMPLES 4 through 20 Other compounds which can be prepared by the procedures of Examples 1, 2 and 3 above are shown below.

These compounds are prepared from the appropriate 35 chloromethyl ether and the appropriate hydroxycarbanilate.

Structure -continued Example No. Structure 16 CH #i-CH,OCH,NHCOO N H C O O C H 17 CH,%\CH -OCH,NHC-O Cl N H --CO --0 CH l8 CI C C-CH,O-CH,NHCO Q N H- C O- 0C H 19 CH;-C I CH,-O-CH,NHCOO NH -C O 0C H 20 CHCI=CHCH,OCH,NH-COO NH-CO -OC H 3 w LA Lambsquaflefi MU Mustard Pl Pigweed EXAMPLE BA Barnyard grass The postemergence herblcidal activity of the pre- 8:25:12 ferred compounds of the inventlon IS demonstrated by W0 Wild Oats the following tests, wherein a variety of monocotyleg8; E83 donous and dicotyledonous plants are treated with test SOY Soybean compounds dispersed in aqueous acetone mixtures. In RAG MG Moming-glory the tests, seedling plants are grown in two-inch square R Rice plastic pots for about two weeks. The test compounds V5 Vdve Leaf are dispersed in 50/50 acetone/water mixtures contain- Difference in Growth mg 0.5% v/v surfactant in sufficient quantity to provide Rating System: from the Check the equivalent of about 0.25 pound to 4 pounds per 0 no 9 0 r of tiv om 0 nd he 1' d t m l ts 36 e 3C e C p U w I n apple I 0 e p an 2 sligh efi-ect H 25 through a spray nozzle operating at 40 psi. for a prede- 3 moderate effect 26-40 termined time. After spraying, the plants are placed on 2 gzfig' f g gg 2:22 greenhouse benches and are cared for in the usual man- 7 good herbicidal efi'ect 76-90 ner, commensurate with conventional greenhouse 8 approaching complete :53

practices. Two weeks after treatment, the seedling plants are examined and rated according to the rating system provided below. The data obtained are reported in the Table III below, where it can be seen that the preferred compounds are highly effective for the control of undesirable broadleaf weeds and grasses.

9 complete kill 4 abnormal growth. i.e. a definite physiological malformation but with an over-all effect less than a 5 on the rating scale.

Based on visual determination of stand. size. vigor. chlorosis. growth malformation and over-all plant appearance.

TABLE lll Postemergence Herbicidal Activity Treatment Annual Weeds Crops Structure lb./Acre a b c d e l" g h i j k l m n CH NH'CO'OCH3 1 9 9 9 s 9 s s 9 8 9 5 9 9 7 HC 5 C-C-O- CH:-NHCO-O 0.25 3 9 5 2 9 2 6 2 I 0 I 8 3 2 CH T 2 I 2 I 0 3 0 6 I 0 O O 3 2 I CH a LA b MU c PI d RAG e MG f BA g CR h GRF i WO j VE k COR l COT m SOY n R vide the equivalent of about 0.25 pound to 2 pounds EXAMPLE 22 per acre of test compound per pot. The treated pots are The preemergence herbicidal activity of the com- 30 then placed on greenhouse benches and cared for in acpounds of the invention is exemplified by the following cordance with greenhouse procedures. Three weeks tests in which the seeds of a variety of monocotyledonafter treatment, the tests are terminated and each pot is ous and dicotyledonous plants are separately mixed examined and rated according to the rating system set with potting soil and the soil-seed mixture are planted forth in the preceding example. The tabulated results of on top of approximately one inch of soil in separate 2- 35 these tests establish the herbicidal proficiency of the inch square plastic pots. After planting, the pots are test compounds for controlling a variety of undesirable sprayed with the selected aqueous acetone solution plant species. Results are reported in Table IV below. containing test compound in sufficient quantity to pro- TABLE IV Preemergc nce Herbicidal Activity Treatment Annual Weeds Crops Structure lbJAcre a b c d e f g h i j k I m n H;C=CH-CH;0CH,NHCO 0 0.5 5 8 8 0 7 0 0 0 O 3 0 0 O 3 CH NHCO 0CH3 I 8 9 9 9 9 7 8 8 7 9 5 9 5 6 HC E C-C--OCH NH--CO O 0.25 7 9 9 8 7 5 6 3 3 8 0 0 O 5 HC i Ci-O--CH NHCOO NH-CO-OCH 2 2 5 3 0 0 0 2 O 0 0 0 O O 0 a LA b MU c Pl d RAG e MG f BA g CR h GRF i WO j VE k COR i COT m SOY n R We claim: 1. A compound of the formula:

II o

wherein R is alkyl C -C alkenyl C C alkynyl C -C cycloalkyl C -C phenyl, benzyl,

A is hydrogen, alkyl C,-C ,-chlorine or bromine; R, is

R and R are hydrogen or alkyl C -C R and R are hydrogen, chlorine or alkyl C -C with the proviso that A and are metaand parato the NHCOR group, respectively, or paraand meta respectively.

2. A compound according to claim 1 wherein R is alkyl C -C 3. A compound according to claim 2, wherein R is 4. A compound according to claim 2 wherein R is UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 914 285 Dated October 21 1975 Inventor(s) Barrington Cross and Charles Paul Grasso It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Please correct the claims as indicated below:

Claim 5. A compound according to Claim 3, carbanilic acid,

m-hydroxy, methyl ester, ester with (allyloxy) methyl]carbamic acid.

Claim 6 A compound according to Claim 4, carbanilic acid,

m-hydroxy, methyl ester, ester with (l,ldimethyl- 2propynyloxy)methyl]carbamic acid.

Claim 7. A compound according to Claim 4, carbanilic acid,

3-chloro-phydroxy-, methyl ester, ester with [(l,l-dimethyl-2-propynyloxy)methyl] carbamic acid. I

Signed and Sealed this seventeenth Day of February 1976 [SEAL] Attest:

C. MARSHALL DANN Arresting Officer 

1. A COMPOUND OF THE FORMULA:
 2. A compound according to claim 1 wherein R is alkyl C1-C6.
 3. A compound according to claim 2, wherein R1 is
 4. A compound according to claim 2 wherein R1 is
 5. A compound according to claim 3, carbonilic acid, m-hydroxy, methyl ester, ester with carbamic acid.
 6. A compound according to claim 4, carbanilic acid, m-hydroxy, methyl ester, ester with carbamic acid.
 7. A compound according to claim 4, carbanilic acid, 3-chloro-p-hydroxy-, methyl ester, ester with carbamic acid. 